1. Field of the Invention
This invention relates generally to drain cleaning devices. More particularly the invention concerns a drain cleaning apparatus for controllably feeding a flexible plumbers snake into a drain line.
2. Description of the Prior Art
A number of different types of devices have been suggested in the past for clearing drain and sewer lines of obstructions. Over the years the construction of these devices has become standardized in many respects. For example, such devices typically include a closed drum, or reel, from which a length of plumbers snake (coiled spring) is paid out. After coming off the reel, the snake is guided into a forwardly disposed guide neck which is substantially in alignment with the axis of the reel. If the snake is not to be paid out by hand, the guide neck is usually provided with snake engagement means which engage the snake so that upon rotation of the drum, or reel, rectilinear movement is imparted to the snake. Thus, if the reel is rotated either direction, the snake can be paid out or taken in.
One of the most commonly used forms of plumber's snake consists of a helically coiled wire. Such snakes are manufactured in several diameters, common sizes being 1/4", 5/16" and 3/8" in diameter. These sizes enable the plumber to cope with stoppages in the various-sized waste pipes usually encountered where hand-held tools are used.
In cleaning out a clogged drain or sewer line, the free end of the snake and guide rod are first introduced into the line. Next, rotation of the drum in a forward direction is initiated using either a hand crank or a motorized drive and finally the snake is paid out by bringing the feed means into engagement with the snake so as to controllably feed it into the line or by hand operation. Feeding of the snake is continued until the obstruction is encountered and loosened.
In actual practice, should the snake encounter a blockage within the line which cannot be loosened, the snake may be caught so that it cannot rotate. In this situation continued rotation of the reel, even for a short period, can cause significant build up of torque forces on the snake within the drum or a distortion or kinking can occur in the coiled snake section between the drain opening and it. If feeding is allowed to continue, these torque forces will cause undesirable back-looping and kinking of the snake within or without the storage drum or reel. Also, this back-looping in turn causes the snake to become tangled within the drum or reel so that the snake can sometimes neither be paid out nor taken in. To rectify this situation, the operator must stop the clean-out operation and somehow relieve the torque build up so that the snake can be untangled. This operation can be both dangerous and time consuming and frequently the operator is simply unable to clear the entanglement sufficiently to continue. It is the solution of this problem of torque build up in the snake to which the present invention is directed.
In the past, various arrangements have been suggested to eliminate or minimize the torque build up and back-looping or kinking in motorized sewer clean-out tools. One of the most successful of these was made by the present inventor and is described in U.S. Pat. No. 3,958,293. Other proposed solutions to the problem are described in U.S. Pat. No. 3,095,592 issued to the present inventor and in U.S. Pat. No. 2,769,191 issued to Robert G. Hunt. The Hunt machine embodied an independently rotatable combination torque reaction element and guide tube which extended into the storage reel from the front of the machine and cooperated therewith to guide the spring into and out of the storage reel and to prevent kinking thereof due to torque build up. The apparatus described in the earlier U.S. Pat. No. 3,958,293 issued to the present inventor improved upon the Hunt concept by providing an independently rotatable, uniquely grooved, torque reaction element which extended into the reel and cooperated with the reel to prevent the snake from kinking or back-looping.
The apparatus described in U.S. Pat. No. 3,095,592 overcomes the back-looping and coiled spring tangling problem by controllably guiding the snake into a restricted volume storage portion of the drum through a strategically placed passageway formed by necking down the drum at a location proximate the periphery thereof.
The apparatus of the present invention approaches the torque build up problem in a different way by providing a unique friction clutch arrangement that automatically stops drum rotation prior to an excessive build up of torque in the snake (coiled spring). With this novel construction, the snake can be smoothly withdrawn from its coiled configuration and, due to the novel action of the clutch mechanism, is automatically prevented from back-looping and tangling up within the storage drum of the snake is caught so that it cannot proceed freely inwardly of the drain line.